The invention concerns a handle for tools, specifically screwdrivers, and is particularly directed to tool handles of the type in which the handle consists of two materials of different hardness. The harder material supporting the tool is not deformable under the forces occurring at operating load, whereas the other material permits slight elastic deformation under load forces. The outside surface of the handle in the axial direction includes successive zones of harder and softer materials.
A handle of this type is disclosed in U.S. Pat. No. 2,871,899. The outside surface of the handle there shown includes, as viewed in its longitudinal direction, successive gripping zones of harder and softer materials. This is accomplished by flexible body sheathing covering a partial length of the cylindrical handle body, with the end area toward the tool amounting to about one-third of the overall length being exposed as a harder gripping zone. To secure it in place, the applied sleeve-type sheathing includes projections which are located inside and are aligned axially with corresponding grooves of the handle core. Such a sheathing of rubber-like material, which can be considered as a substantially complete sheathing, is disadvantageous in use; it proves to be "spongy". Especially in sustained use, irritations and even inflammations are caused by walking wrinkles and increased static friction. As a result, the tool is unsuited for sustained use. The short, harder gripping zone is additionally reduced in diameter and is primarily used for so-called "twisting", that is, for starting the screw under light load. The application of a higher torque is reserved, though, to the area of the handle end with the soft sheathing.
Another handle is disclosed in German Patent Document No. 1 298 060 which describes a screwdriver handle which is specifically designed for applying a high torque. This handle enables a good seating of the handle in the operator's hand. A plurality of separate flutes are arranged on the circumference of the handle body in angled relationship to one another. These separate flutings provide a safe grip.
The problem underlying the invention is to provide a tool of the type in question which is simple to manufacture and advantageous in use. The handle enables torques to be transmitted and the grip is considerably improved and is more sympathetic to the hand.